Death toll hits 140 as swine flu goes global

Concerns about how some countries might react to an official declaration of a full-blown influenza pandemic are preventing the World Health Organisation (WHO) from raising its current alert status to the highest level and admitting that a global flu epidemic is under way.

Senior scientists have told The Independent that the pandemic flu plans of many countries are too rigid and that were one to be declared by the WHO it would automatically mean that those nations would enact draconian measures – such as school closures – that could cause panic.

The experts claim that the problem stems from the fact that many countries have based their plans on the possibility of a pandemic being caused by a more lethal strain of bird flu, rather than the relatively mild strain of H1N1 swine flu that has spread from Mexico and North America to South America, Europe, Asia, Japan and Australia.

"The issue of declaring a pandemic does have implications for how a country responds. So the final decision [on whether to declare a pandemic] depends on weighing up the pros and cons of how the world will react and how different countries will be affected," said one WHO scientist.

Most specialists agree that the WHO could decide the swine flu crisis is now at the stage where it could be justifiably upgraded to a full-blown pandemic, which is defined as the virus spreading freely within the wider communities of at least two WHO regions.

Experts believe that the spread of the virus in Mexico and the US is now on the verge of being matched by its spread in parts of Europe – notably Britain and Spain – as well as Chile and Australia, where the number of cases has exploded past 1,000 within the past few days.

However, earlier this week the head of the WHO's global influenza programme, Keiji Fukuda, admitted that the health organisation is worried about a "blossoming of anxiety" if it declares a full-scale pandemic. "We are getting close to knowing that we are in a pandemic situation... One of the critical issues is that we do not want people to panic," he said.

Professor Neil Ferguson of Imperial College London said that moving from the current phase five – meaning that a pandemic is imminent – to the final phase six, when a pandemic is in full swing, could result in an over-reaction in some countries. "If we move to phase six, lots of countries will trigger pandemic plans that may be too costly to justify. Many of the plans were designed for bird flu or the kind of lethal flu virus that caused the 1918 pandemic. That kind of mortality would justify draconian actions," Professor Ferguson said.

"Some countries have rigid plans and to enact them would be costly. There's a whole set of policy decisions that have to be considered," he added. In Britain, a further 42 new cases of swine flu yesterday brought the total number of confirmed cases to 750. Worldwide, the WHO reported a total of 27,737 cases, including 141 deaths, in 74 countries. Outside North America, the worst-affected countries are Chile, with nearly 1,700 cases, and Australia, with more than 1,200 cases. It is now clear that the virus has gained footholds in several countries in the southern hemisphere that are about to enter their flu season with the onset of winter.

One fear is that it could spread rapidly in the region over the coming months and mutate into a more dangerous form that could then come back to the northern hemisphere this winter to cause more severe flu.

"The main concern now is what will happen in the countries of the southern hemisphere that are now coming into their winter," said Professor Alan Hay of the National Institute for Medical Research in Mill Hill, north London. "The real concerns are Australia and particularly Chile, as it is top of the list in terms of number of cases in South America.

"In Australia, it is quite clear that the virus has spread within the community there. It really does look like it has taken hold in the southern hemisphere and we'll see pretty soon whether it will cause a pandemic," he added.

A history of pandemics

* If the WHO declares a flu pandemic it will be the first time it has done so since 1968.

* There have been three influenza pandemics in the 20th century. The first, in 1918, may have killed between 50 million and 100 million people. It is now known to have been caused by the H1N1 strain of the virus.

* The second in 1957 was caused by a strain called HN2 and was known as Asian flu. It came in several waves of varying severity between 1957 and 1960.

* A third pandemic in 1968, called Hong Kong flu, occurred in waves and was caused by the H3N2 strain.

* Experts believe that the current strain of H1N1 flu may follow the same pattern and that the relatively mild symptoms seen in patients now may become more severe in time.

* Studies of previous pandemics give few clues about how the present outbreak may develop. It may peter out with relatively few deaths, or it may return with a vengeance this winter.